What Is an Osage Orange?

Overview

Although the Osage orange tree isn't particularly ornamental or a feature plant in a garden, it is grown across USDA hardiness zones 5 through 9, often as in hedgerows. This tree (Maclura pomifera) produces warty, light greenish yellow fruits that also are called Osage oranges. According to Dr. Michael Dirr of the University of Georgia, Newton's Law of Gravity "had nothing to do with falling apples; falling Osage oranges prompted the theory." The tree is tolerant of heat and dry soils, making it a tough plant that also bear thorns in its branches.

Origins

The Osage orange tree is native to the south-central United States, from Arkansas to Oklahoma and Texas.

Name Etymology

"Osage orange" is so-named because the native range of the plant is almost identical to the region where the Native American tribes of Osage lived on the southern Great Plains. The fruits smell of the sweet rind of a real citrus orange.

Tree Characteristics

Typically growing 20 to 40 feet tall and 15 to 35 feet wide, old specimens have the potential to grow to 60 feet in height. The canopy is rounded with thorny branches (especially when the tree is young) and lined with pointed oval leaves. The tree is deciduous in winter. Osage orange trees are either male or female in gender as noted by the flowers. In early summer the trees bear their yellow-green flowers that are tiny and unshowy. Female trees bear their flowers on short branching structures and male trees in dense, rounded clusters. Only female trees develop the Osage orange fruits. In autumn the leaves turn yellow before falling off.

The Osage Orange Fruit

Usually 5 to 6 inches in diameter, the Osage orange or "hedge apple" develops over the mid- and late summer with a warty skin and light green color. By autumn the fruit's skin turns more yellow-green and eventually to light yellow by the time the leaves drop away. These citrus-fragrant fruits persist on the tree branches well into winter, although the sheer weight of some causes them to drop to the ground.

Are Osage Oranges Edible?

Yes, they're edible, but only the seeds. Break open an Osage orange and you will find a grainy pith with embedded seeds. Sticky, white liquid accompanies the pith fibers. Each seed, which is smaller than a sunflower seed in size, is sheathed in a slimy husk. There are upwards of 200 seeds in one fruit, according to the Great Plains Nature Center.

Keywords: Osage orange, thorny trees, Maclura pomifera, warty green fruits

About this Author

James Burghardt has written for "The Public Garden," "Docent Educator," nonprofit newsletters and for horticultural databases, becoming a full-time writer in 2008. He's gardened and worked professionally at public and private gardens in Colorado, Florida, Minnesota, New York, North Carolina and Pennsylvania. He has written articles for eHow and GardenGuides.